Various methods are known in the art for remote tracking of a movable object within a controlled area. For example, radio frequency (RF) identification tags may be fixed to objects in the area. Each tag typically comprises an RF transceiver, which transmits a unique identification code when queried by a signal from a central antenna. Such systems may be capable of identifying multiple objects, but they generally give only a rough indication of the location of each object. Optical markers can be tracked using video cameras to obtain more accurate position information. Optical systems of this sort, however, generally require the use of sophisticated and costly image processing equipment, and are limited in the number of objects that they can track simultaneously.